Hello everyone, I am new here, but I did some research before posting my question and wasn't able to find a sufficient answer, I am attempting to make a water level indicator for my daughters fish tank. I am using Arduino uno with a LCD 20x4 with IC2 backpack and water sensor from a ELEGOO sensor kit. I have successfully made the proto type, however when the water sensor is not in the water the LCD is very bright, and when the water sensor is submersed in water the LCD dims quite a bit.
I will note that I am powering from the 5v on the uno board.
I would appreciate any insight that anyone could offer.
That sounds like a fairly serious wiring problem.
If you were to read and follow the directions in the "How to get the best out of this forum" post (linked at the head of every forum category), and provide the needed information about your project, forum members might be able to help.
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+1 for what @jremington posted. Please read the forum guidelines.
When you post a question that pertains to hardware a schematic is a must. Written descriptions are always more ambiguous than a drawing. Hand drawn, photographed and posted is fine. Include all pin names/numbers, components, their part numbers and/or values and power supplies.
We also need to see data sheets or some other technical documentation for each relevant component.
Photos of the project can also be helpful.
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show what you get.
and schematic, and picture of setup, and sketch.
The notes didn't attach on the schematic.
A1 & A2 are connected to a water temp and pH meter... PH4502C. I have calibrated but not yet tested water with that.
A3 is connected to the water sensor, which works correctly reading high, medium, and low, water levels, but the display dims very noticeably when the sensor contacts water.
on tinkercad diagram VCC and GND not connected to breadboard rails
We need to see which terminals of the sensor go to what pins on the Arduino.
We need to see the pinout of the sensor. A data sheet for the sensor would help.
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you are correct,
they are connected on the prototype...
from my photo: orange is positive connection on bread board, black is negative connection on bread board, and the blue is connected to A3, I tried my best to get a photo that would let you trace the blue wire at least.
I have also tried to power and ground the sensor directly from the Arduino with the remaining 5v and ground port, but the results did not change. the LCD still dims when the water sensor makes contact with liquid.
Hi,
Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?
Hand drawn and photographed is perfectly acceptable.
Please include ALL hardware, power supplies, component names and pin labels.
A Fritzy cut and paste does not show all the information needed.
Thanks.. Tom.... 
The LCD dimming suggests excessive current draw, perhaps a short circuit somewhere in contact with the water.
Are you able to check the voltage at the VCC and GND pins of the LCD while the sensor is in the air and then in water? And also the same for the sensor VCC and GND.
Hi, @x404241889
Why is the power into the sensor coming from Vin and not 5V.
They are not the same.
Do you have a DMM? (Digital MultiMeter)
PLEASE draw a circuit diagram, reverse engineer your project.
Tom...
Do you mean the BACK LIGHT dims or the characters on the LCD dim?
It looks like your characters "dim" or are displayed then blanked repeatedly very quickly...
Please post your code.
To add code please click this link;
Thanks.. Tom..
Tom,
You are very correct sir, I had power from Vin an d not the 5v. When connected to the 5v power from the board and the sensor dips into water no dimming of characters or back light occur. problem solved.
I might run into some on the code, that i am working on today.
I greatly appreciate your help, everyone! I am very much a novice, and having a helpful community encourages other novices such as myself to continue to learn.
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